Big port overheat problem

anyzunstudios
Posts: 4
Joined: Wed Feb 06, 2019 11:31 pm

Big port overheat problem

Postby anyzunstudios » Sat Jul 18, 2020 3:26 pm

Hello everyone,

I have a T16 Toyota Celica with a Late Big Port 4AGE with overheat problems.

It started one night driving normally on a mountain pass and engine got over 100°C, so I stopped it and call the insurance to tow it (my first time with this temp).

Next day I dryed the water circuit and changed all water sensors and thermostat (btw the radiator is new). I purged the water system but it keeps getting really hot and the fan never turns on.

I removed the thermo-switch and the fan turned on, so fan and circuit works fine.

I tested the new and old thermostat with hot water and both worked fine. I bought a third one and it also worked fine.

I decided to open the radiator cap and I saw that water never moves when engine temp is more than 83°C or more. I touched the tube that goes from water pump to the radiator and it was like enpty, so I started to think that something is clogged.

I removed the tube that returns from water pump to radiator and I saw that the water flow coming from water pump to radiator was almost nothing when idling, but pressing the throttle whater flow raises a bit but not as expected.

Looks like a stuck or broken water pump? I think is the stock one that car came with.

Thanks in advance!

Regards.

davew7
Club4AG Expert
Posts: 200
Joined: Fri Jun 06, 2014 4:34 am
Location: Michigan

Re: Big port overheat problem

Postby davew7 » Sun Jul 19, 2020 3:47 am

With the fan belt off, if you turn the water pump by hand do you feel any resistance or play in the shaft? It does sound like the water pump. I would say you got your monies worth if it the original pump. Really not that bad of a job to replace.
Just do not over tighten the belt when installing. Davew7

User avatar
jondee86
Moderator
Posts: 2711
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: Big port overheat problem

Postby jondee86 » Sun Jul 19, 2020 3:12 pm

Does your cooling system look like this...

Image

If it does, then it will rely on hot coolant flowing down the smaller "bypass pipe/hose"
to heat and activate the thermostat. If the bypass is blocked then the thermostat will
stay closed and prevent coolant leaving the radiator. At least I think that is how it works :)

So it might be worth checking to see if the bypass hose heats up as the engine warms
up. If it stays cold while everything else gets hot it may be blocked. You could even try
running the engine without a thermostat installed. That way you should at least get
coolant circulating through the radiator if the pump is doing its job. If you don't get
any circulation then as said above... time for a new pump.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

allencr
Club4AG Expert
Posts: 375
Joined: Thu Jan 10, 2013 9:59 pm

Re: Big port overheat problem

Postby allencr » Mon Jul 20, 2020 2:13 am

Water pump failure is extremely rare, I've never seen one but I've heard of Many water pumps being replaced for reasons only slightly related to it.
Not that water pumps don't fail, they leak & their bearing goes bad, but failing to actually pump is almost unheard of, a few have broken impellers or corroded away.
Also, 'new radiator' means nothing as it can get clogged immediately after an overheat that has loosened up a lot of junk. Can you see that it's tubes are clear & clean of any debris????? Internally, check outside too.

Check the thermostat.

anyzunstudios
Posts: 4
Joined: Wed Feb 06, 2019 11:31 pm

Re: Big port overheat problem

Postby anyzunstudios » Mon Jul 20, 2020 5:58 am

davew7 wrote:With the fan belt off, if you turn the water pump by hand do you feel any resistance or play in the shaft? It does sound like the water pump. I would say you got your monies worth if it the original pump. Really not that bad of a job to replace.
Just do not over tighten the belt when installing. Davew7


In my case my Celica had electric fan, so I need to remove the alternator belt. What I started to hear is a noise from engine when I press the throttle and I am going up on a mountain pass or getting out of an underground parking.

anyzunstudios
Posts: 4
Joined: Wed Feb 06, 2019 11:31 pm

Re: Big port overheat problem

Postby anyzunstudios » Mon Jul 20, 2020 6:09 am

jondee86 wrote:Does your cooling system look like this...

Image

If it does, then it will rely on hot coolant flowing down the smaller "bypass pipe/hose"
to heat and activate the thermostat. If the bypass is blocked then the thermostat will
stay closed and prevent coolant leaving the radiator. At least I think that is how it works :)

So it might be worth checking to see if the bypass hose heats up as the engine warms
up. If it stays cold while everything else gets hot it may be blocked. You could even try
running the engine without a thermostat installed. That way you should at least get
coolant circulating through the radiator if the pump is doing its job. If you don't get
any circulation then as said above... time for a new pump.

Cheers... jondee86


Yeah my system is like you shows on the pic. I will try it this afternoon, but the low flow of water returning seems that pump is not working at all. I opened the efi sensor hole and I saw new water inside, so it looks like engine has water inside and its not blocked from water intake to block. When I refill the circuit I saw at about 82°C the water level went down, so thermostat worked.

If water pump is not working properly and no water is returning maybe that make the fan to not turn on? Sensor is before thermostat entrance.

Greetings and thanks!

anyzunstudios
Posts: 4
Joined: Wed Feb 06, 2019 11:31 pm

Re: Big port overheat problem

Postby anyzunstudios » Mon Jul 20, 2020 6:13 am

allencr wrote:Water pump failure is extremely rare, I've never seen one but I've heard of Many water pumps being replaced for reasons only slightly related to it.
Not that water pumps don't fail, they leak & their bearing goes bad, but failing to actually pump is almost unheard of, a few have broken impellers or corroded away.
Also, 'new radiator' means nothing as it can get clogged immediately after an overheat that has loosened up a lot of junk. Can you see that it's tubes are clear & clean of any debris????? Internally, check outside too.

Check the thermostat.


Previous owner had the engine with normal water and on the old times people didn’t use coolant at all, and I had to clean the cooling system a bunch of times and even today is a bit dirty, and water looks darker than it should, but no oil on it.

About thermostat, I checked the one it had installed and 2 new ones and all of them worked perfectly with hot water.

User avatar
jondee86
Moderator
Posts: 2711
Joined: Fri Jan 11, 2013 10:21 pm
Location: Wellington, New Zealand

Re: Big port overheat problem

Postby jondee86 » Mon Jul 20, 2020 2:29 pm

If your engine ran for many years with plain water instead of coolant with a corrosion
inhibitor, your water pump could look like this...

Image

The vanes on the pump impeller are made from folder sheetmetal and will gradually
rust away until they look like the pic or even worse. Once they lose enough surface
the ability to move coolant reduces and eventually stops when all the fins are gone.

In addition to this, corrosion forms a thick layer of rust on the inside of small steel
tubes reducing the inside diameter. Loose bits of rust circulating with the coolant can
get stuck in these narrowed tubes and block them completely.

I'd say it is time to replace the water pump. If that does not solve your problem it will
at least eliminate one possibility. You can also check for blockages in the steel tubes
at the rear of the engine and in the bypass section. The water pump is actually
considered to be a service item and is often replaced as a matter of course when the
cambelt is replaced.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

24milespergallon
Posts: 6
Joined: Tue Jan 06, 2015 8:20 pm

Re: Big port overheat problem

Postby 24milespergallon » Wed Sep 23, 2020 2:46 pm

did you solve your overheating issue?